The cross-section stratifications of samples, which were removed from six icons, are studied usin... more The cross-section stratifications of samples, which were removed from six icons, are studied using optical microscopy, micro-Raman spectroscopy, and micro-Fourier transform infrared (FT-IR) spectroscopy. The icons, dated from the 14th to 19th centuries, are prominent examples of Byzantine painting art and are attributed to different artistic workshops of northern Greece. The following materials are identified in the cross-sections of the icon samples using micro-Raman spectroscopy: anhydrite; calcite; carbon black; chrome yellow; cinnabar; gypsum; lead white; minium; orpiment; Prussian blue; red ochre; yellow ochre; and a paint of organic origin which can be either indigo ( Indigofera tinctoria L. and others) or woad ( Isatis tinctoria L.). The same samples are investigated using micro-FT-IR which leads to the following identifications: calcite; calcium oxalates; chrome yellow; gypsum; kaolinite; lead carboxylates; lead sulfate (or quartz); lead white; oil; protein; Prussian blue;...
Since ancient times, it has been noticed that Goji berry fruit juice, roots and leaves consist of... more Since ancient times, it has been noticed that Goji berry fruit juice, roots and leaves consist of ingredients that contain a wide variety of bioactive substances. The consumption of goji berry fruits results in properties which improve the subjective feeling of general well-being. The aim of this work is to present the information from the existing literature on the possible role of goji berry plant parts and their extracts as a functional food. Lycium barbarum Polysaccharides (LBP) and polyphenols are the most researched aspects of fruits associated with the promotion of human health. Goji berry fruits demonstrated anti-oxidative properties that are associated with age-related diseases such as diabetes, atherosclerosis and antitumor and immunoregulatory activities. Bioactive secondary metabolites contained in fruit lead to positive effects for human vision, while other biochemicals contained in the root bark have shown hepatoprotective and inhibitory actions on the rennin/angiotens...
Supplemental material for Investigation of the Cross-Section Stratifications of Icons Using Micro... more Supplemental material for Investigation of the Cross-Section Stratifications of Icons Using Micro-Raman and Micro-Fourier Transform Infrared (FT-IR) Spectroscopy by Dimitra Lazidou, Dimitrios Lampakis, Ioannis Karapanagiotis and Costas Panayiotou in Applied Spectroscopy
In this work we provide results of three analytical methods, e.g. micro-RAMAN, micro-FTIR and SEM... more In this work we provide results of three analytical methods, e.g. micro-RAMAN, micro-FTIR and SEM/EDS, which were applied for the identification of pigments in 19th century icons for preservation and restoration purposes. These icons are stored in the Saint George church at the Asvestochori village near Thessaloniki, N. Greece. The two icons depict the “Palpation of Thomas” and St.Dionisios, respectively, and were constructed between 1812 and 1825 to decorate the altar of the church. These icons are works of folk art and their iconographic characteristics are affected by the contemporaneous historic spirit. Thus, the saints are depicted in simple shapes, primary colors are dark and locally mixed with brighter tones to express a hint of joy. Icons are in good conservation status, they exhibit usage and time ravages to their paint layers and wooden bodies. Representative samples, of the pigments, not exceeding dimensions of approximately 2x3x1 mm, from both icons were obtained. These samples were studied using the non-destructive technique of micro-Raman spectroscopy for the identification of inorganic pigments. Micro-FTIR spectroscopy was implemented as a complementary technique for the identification purposes. Finally, where coatings of the binder material on the pigments were hampering the spectroscopy analyses the scanning electron microscopy (SEM/EDS) technique was selectively used. The analytical techniques micro-RAMAN and micro-FTIR were performed in the frame of the “Programme of Management and Conservation of Ecclesiastical Cultural Heritage Objects” at the University Ecclesiastical Academy of Thessaloniki. The SEM/EDS study was applied at the School of Sciences of Aristotle University of Thessaloniki. The main purpose of this study is to improve our scientific knowledge on the pigments which were used at iconography during early 19th century in the broader area of Thessaloniki, by examining inorganic and organic components and when possible to apply these materials in the conservation science.
The interest in using plant by-product extracts as functional ingredients is continuously rising ... more The interest in using plant by-product extracts as functional ingredients is continuously rising due to environmental and financial prospects. The development of new technologies has led to the achievement of aqueous extracts with high bioactivity that is preferable due to organic solvents nonuse. Recently, widely applied and emerging technologies, such as Simple Stirring, Pressure-Applied Extraction, Enzymatic Extraction, Ultrasound-Assisted Extraction, Pulsed Electric Fields, High Hydrostatic Pressure, Ohmic Heating, Microwave Assistant Extraction and the use of “green” solvents such as the deep eutectic solvents, have been investigated in order to contribute to the minimization of disadvantages on the extraction of bioactive compounds. This review is focused on bioactive compounds derived from pomegranate (Punica granatum) peels and highlighted the most attractive extraction methods. It is believed that these findings could be a useful tool for the pomegranate juices industry to ...
Journal of Food Measurement and Characterization, 2019
The present study aimed at assessing the antimicrobial properties of a water and ethanol ultrasou... more The present study aimed at assessing the antimicrobial properties of a water and ethanol ultrasound-assisted extraction (UAE) of dry goji berries and of lyophilised powdered pomegranate peel in vitro. Minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) methods, turbidity (cell density) measurement, and well diffusion assay were used to determine the antimicrobial activity against several species of foodborne bacteria (Gram – , Escherichia coli, Salmonella typhimurium, Campylobacter jejuni), (Gram + Staphylococcus aureus, Listeria monocytogenes, Clostridium perfringens), yeasts (Yarrowia lipolytica, Metschnikowia fructicola, and Rhodotorula mucilaginosa), and fungi (Penicillium expansum, Aspergillus niger, Fusarium oxysporum, and Rhizoctonia solani). Carbohydrate and phenolic contents were measured, and DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2΄-Azino-bis-(3-ethyl-benzthiazoline-sulphonic acid)) radical scavenging assays were used for the assessment of antioxidant activity. Fourier transform infrared (FTIR) spectrums of all samples were also evaluated in order to determine their chemical profiles. The lyophilised pomegranate peel exhibited the highest antioxidant, antimicrobial, and antifungal activity among all samples, while among the goji berry samples-who had only antibacterial and very little or no antifungal activity—the lyophilised aqueous extract with the lowest content of maltodextrin (2%) and highest phenolic content, had also the highest antioxidant, antimicrobial, and antifungal activity. The antioxidant and antimicrobial bioactivities seemed to be related to the content of polyphenols, the low concentration of maltodextrin in the encapsulated lyophilised samples and the use of optimised ultrasound assisted extraction. Minimum inhibitory concentration or zones of inhibition were in many (but not all) cases lower for the aqueous extracts compared to the ethanol or ethanol/hexane extracts of goji berries. In conclusion, the lyophilized powder of pomegranate peels and the aqueous extracts of goji berries encapsulated with minimal maltodextrin content and high polyphenol content exhibited high antioxidant and antimicrobial activity which could be utilized in food preservation or plant protection.
ABSTRACT The stratigraphies of twenty five (25) samples removed from twenty (20) icons of the Cre... more ABSTRACT The stratigraphies of twenty five (25) samples removed from twenty (20) icons of the Cretan School of iconography are studied using Optical Microscopy and micro-Raman spectroscopy. The objects are dated in 15th–17th c. and belong to the collection of the Benaki Museum, Athens, Greece. Cinnabar, red ochre, minium, yellow ochre, azurite, malachite, lapis lazuli, lead white, carbon black, and indigo are identified in the cross-sections of the icon samples using Raman spectroscopy.For four (4) icons no data were available from previous investigations regarding the identity of the red organic colourants. Microsamples were extracted from these icons and analysed using High Performance Liquid Chromatography coupled to a Diode Array Detector (HPLC–DAD). The HPLC–DAD results provide support to recently published reports which showed that kermes used in Cretan icons of the early period was replaced by cochineal after the discovery of the New World. The study of the cross-sections of the icon samples with Optical Microscopy revealed the combinations of the various inorganic and organic colourants.
In this study, the content composition and antioxidant activity of goji berry fruits from two spe... more In this study, the content composition and antioxidant activity of goji berry fruits from two species (Lycium barbarum and Lycium chinense) were assessed. The total carbohydrate and phenolic contents were evaluated using attenuated total reflection Fourier-transform infrared (ATR-FT-IR) spectroscopy, while the antioxidant activity of fruits was examined with two in vitro methods, which are based on the scavenging activity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2’-azino-bis(3-ethyl-benzthiazoline-sulfonic acid) (ABTS•+) free radicals. The fatty-acid profile was determined using gas chromatography coupled with mass spectrometry (GC-MS). The results of this study indicate that the fruits of L. barbarum present higher concentrations in carbohydrates and phenolics than L. chinense Mill. fruits. Furthermore, the antioxidant activity based on the half maximal inhibitory concentration (IC50) measurements of DPPH• and ABTS•+ free-radical scavenging was higher in L. barbarum than ...
The cross-influence effects of treatment temperature and time on the wettability of a siloxane el... more The cross-influence effects of treatment temperature and time on the wettability of a siloxane elastomer is investigated in detail, through static and tilt contact angle measurements. The material is heated at 400, 500, 600, 650, 700, and 800 °C for various periods, ranging from 1 to 300 s. The siloxane surface is subjected to multiple wettability transitions with treatment time: from intrinsic hydrophobicity to superhydrophobicity (and water repellency) and then through intermediate stages (hydrophobicity and hydrophilicity) to superhydrophilicity. For the time scale used herein (1-300 s), this scenario is recorded for treatment at 650, 700, and 800 °C. For treatment at lower temperatures (400, 500, and 600 °C) only the first transition, from intrinsic hydrophobicity to superhydrophobicity, is recorded. Scanning electron microscopy, micro-Fourier transform infrared (micro-FTIR), and micro-Raman spectroscopies are employed to correlate the aforementioned wettability transitions with structural and chemical changes of the siloxane surface, developed during thermal treatment. It is shown that the first transition from intrinsic hydrophobicity to superhydrophobicity is accompanied by a severe surface-structure evolution that increases surface roughness. Once superhydrophobicity is achieved, the surface structure reaches a saturation point and it is not subjected to any other change with further thermal treatment. FTIR spectroscopy shows that the intensity of the O-H/C-H peaks increases/decreases with treatment time, and Raman measurements show that the C-Si-C vibrations gradually disappear with treatment time. The evaporation of a droplet resting on a superhydrophobic, water-repellent siloxane surface, which was produced after appropriate thermal treatment, is monitored. It is shown that droplet evaporation initially follows the constant contact area mode. At later evaporation stages, a transition to the constant contact angle mode is recorded. Finally, it is demonstrated that the superhydrophobic and water-repellent siloxane surfaces exhibit self-cleaning properties, good durability, and furthermore do not practically affect the optical transparency of glass substrates.
Abstract. The spin and orbital ordering have been examined for high-quality SmVO3 polycrystalline... more Abstract. The spin and orbital ordering have been examined for high-quality SmVO3 polycrystalline compound using Raman spectroscopy. Measurements were obtained on individual microcrystallites in the approximate y(zz)y ̄ and y(xx)y ̄ scattering configurations at low temperatures (down to 20K). Based on our experimental data we present evidence of a coexistence of the G and C-type OO phases that occur in SmVO3 for temperatures below 100K. This phase coexistence of orbital orderings puts SmVO3 in a different category from all the other RVO3 compounds that have been studied yet. 1.
a b s t r a c t The doping dependence of the Raman spectra of high quality La 2Àx Sr x Cu À1 , $2... more a b s t r a c t The doping dependence of the Raman spectra of high quality La 2Àx Sr x Cu À1 , $280 cm À1 , and $370 cm À1 are activated in the (xx/yy) polarization Raman spectra due to the local breaking of the inversion symmetry mainly at low temperatures and for doping concentrations for which the compound is superconducting. The apparent A 1 -character of the activated modes in the symmetry reduced phase indicates a reduction from the D 2h to C 2v or D 2 crystal symmetries, which associates the observed modes to specific IR-active phonons with eigenvectors mainly along the c-axis. The temperature and doping dependence of this inversion symmetry breaking and the superconducting transition temperature are very similar, though the symmetry reduction occurs at significantly higher temperatures.
The cross-section stratifications of samples, which were removed from six icons, are studied usin... more The cross-section stratifications of samples, which were removed from six icons, are studied using optical microscopy, micro-Raman spectroscopy, and micro-Fourier transform infrared (FT-IR) spectroscopy. The icons, dated from the 14th to 19th centuries, are prominent examples of Byzantine painting art and are attributed to different artistic workshops of northern Greece. The following materials are identified in the cross-sections of the icon samples using micro-Raman spectroscopy: anhydrite; calcite; carbon black; chrome yellow; cinnabar; gypsum; lead white; minium; orpiment; Prussian blue; red ochre; yellow ochre; and a paint of organic origin which can be either indigo ( Indigofera tinctoria L. and others) or woad ( Isatis tinctoria L.). The same samples are investigated using micro-FT-IR which leads to the following identifications: calcite; calcium oxalates; chrome yellow; gypsum; kaolinite; lead carboxylates; lead sulfate (or quartz); lead white; oil; protein; Prussian blue;...
Since ancient times, it has been noticed that Goji berry fruit juice, roots and leaves consist of... more Since ancient times, it has been noticed that Goji berry fruit juice, roots and leaves consist of ingredients that contain a wide variety of bioactive substances. The consumption of goji berry fruits results in properties which improve the subjective feeling of general well-being. The aim of this work is to present the information from the existing literature on the possible role of goji berry plant parts and their extracts as a functional food. Lycium barbarum Polysaccharides (LBP) and polyphenols are the most researched aspects of fruits associated with the promotion of human health. Goji berry fruits demonstrated anti-oxidative properties that are associated with age-related diseases such as diabetes, atherosclerosis and antitumor and immunoregulatory activities. Bioactive secondary metabolites contained in fruit lead to positive effects for human vision, while other biochemicals contained in the root bark have shown hepatoprotective and inhibitory actions on the rennin/angiotens...
Supplemental material for Investigation of the Cross-Section Stratifications of Icons Using Micro... more Supplemental material for Investigation of the Cross-Section Stratifications of Icons Using Micro-Raman and Micro-Fourier Transform Infrared (FT-IR) Spectroscopy by Dimitra Lazidou, Dimitrios Lampakis, Ioannis Karapanagiotis and Costas Panayiotou in Applied Spectroscopy
In this work we provide results of three analytical methods, e.g. micro-RAMAN, micro-FTIR and SEM... more In this work we provide results of three analytical methods, e.g. micro-RAMAN, micro-FTIR and SEM/EDS, which were applied for the identification of pigments in 19th century icons for preservation and restoration purposes. These icons are stored in the Saint George church at the Asvestochori village near Thessaloniki, N. Greece. The two icons depict the “Palpation of Thomas” and St.Dionisios, respectively, and were constructed between 1812 and 1825 to decorate the altar of the church. These icons are works of folk art and their iconographic characteristics are affected by the contemporaneous historic spirit. Thus, the saints are depicted in simple shapes, primary colors are dark and locally mixed with brighter tones to express a hint of joy. Icons are in good conservation status, they exhibit usage and time ravages to their paint layers and wooden bodies. Representative samples, of the pigments, not exceeding dimensions of approximately 2x3x1 mm, from both icons were obtained. These samples were studied using the non-destructive technique of micro-Raman spectroscopy for the identification of inorganic pigments. Micro-FTIR spectroscopy was implemented as a complementary technique for the identification purposes. Finally, where coatings of the binder material on the pigments were hampering the spectroscopy analyses the scanning electron microscopy (SEM/EDS) technique was selectively used. The analytical techniques micro-RAMAN and micro-FTIR were performed in the frame of the “Programme of Management and Conservation of Ecclesiastical Cultural Heritage Objects” at the University Ecclesiastical Academy of Thessaloniki. The SEM/EDS study was applied at the School of Sciences of Aristotle University of Thessaloniki. The main purpose of this study is to improve our scientific knowledge on the pigments which were used at iconography during early 19th century in the broader area of Thessaloniki, by examining inorganic and organic components and when possible to apply these materials in the conservation science.
The interest in using plant by-product extracts as functional ingredients is continuously rising ... more The interest in using plant by-product extracts as functional ingredients is continuously rising due to environmental and financial prospects. The development of new technologies has led to the achievement of aqueous extracts with high bioactivity that is preferable due to organic solvents nonuse. Recently, widely applied and emerging technologies, such as Simple Stirring, Pressure-Applied Extraction, Enzymatic Extraction, Ultrasound-Assisted Extraction, Pulsed Electric Fields, High Hydrostatic Pressure, Ohmic Heating, Microwave Assistant Extraction and the use of “green” solvents such as the deep eutectic solvents, have been investigated in order to contribute to the minimization of disadvantages on the extraction of bioactive compounds. This review is focused on bioactive compounds derived from pomegranate (Punica granatum) peels and highlighted the most attractive extraction methods. It is believed that these findings could be a useful tool for the pomegranate juices industry to ...
Journal of Food Measurement and Characterization, 2019
The present study aimed at assessing the antimicrobial properties of a water and ethanol ultrasou... more The present study aimed at assessing the antimicrobial properties of a water and ethanol ultrasound-assisted extraction (UAE) of dry goji berries and of lyophilised powdered pomegranate peel in vitro. Minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) methods, turbidity (cell density) measurement, and well diffusion assay were used to determine the antimicrobial activity against several species of foodborne bacteria (Gram – , Escherichia coli, Salmonella typhimurium, Campylobacter jejuni), (Gram + Staphylococcus aureus, Listeria monocytogenes, Clostridium perfringens), yeasts (Yarrowia lipolytica, Metschnikowia fructicola, and Rhodotorula mucilaginosa), and fungi (Penicillium expansum, Aspergillus niger, Fusarium oxysporum, and Rhizoctonia solani). Carbohydrate and phenolic contents were measured, and DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2΄-Azino-bis-(3-ethyl-benzthiazoline-sulphonic acid)) radical scavenging assays were used for the assessment of antioxidant activity. Fourier transform infrared (FTIR) spectrums of all samples were also evaluated in order to determine their chemical profiles. The lyophilised pomegranate peel exhibited the highest antioxidant, antimicrobial, and antifungal activity among all samples, while among the goji berry samples-who had only antibacterial and very little or no antifungal activity—the lyophilised aqueous extract with the lowest content of maltodextrin (2%) and highest phenolic content, had also the highest antioxidant, antimicrobial, and antifungal activity. The antioxidant and antimicrobial bioactivities seemed to be related to the content of polyphenols, the low concentration of maltodextrin in the encapsulated lyophilised samples and the use of optimised ultrasound assisted extraction. Minimum inhibitory concentration or zones of inhibition were in many (but not all) cases lower for the aqueous extracts compared to the ethanol or ethanol/hexane extracts of goji berries. In conclusion, the lyophilized powder of pomegranate peels and the aqueous extracts of goji berries encapsulated with minimal maltodextrin content and high polyphenol content exhibited high antioxidant and antimicrobial activity which could be utilized in food preservation or plant protection.
ABSTRACT The stratigraphies of twenty five (25) samples removed from twenty (20) icons of the Cre... more ABSTRACT The stratigraphies of twenty five (25) samples removed from twenty (20) icons of the Cretan School of iconography are studied using Optical Microscopy and micro-Raman spectroscopy. The objects are dated in 15th–17th c. and belong to the collection of the Benaki Museum, Athens, Greece. Cinnabar, red ochre, minium, yellow ochre, azurite, malachite, lapis lazuli, lead white, carbon black, and indigo are identified in the cross-sections of the icon samples using Raman spectroscopy.For four (4) icons no data were available from previous investigations regarding the identity of the red organic colourants. Microsamples were extracted from these icons and analysed using High Performance Liquid Chromatography coupled to a Diode Array Detector (HPLC–DAD). The HPLC–DAD results provide support to recently published reports which showed that kermes used in Cretan icons of the early period was replaced by cochineal after the discovery of the New World. The study of the cross-sections of the icon samples with Optical Microscopy revealed the combinations of the various inorganic and organic colourants.
In this study, the content composition and antioxidant activity of goji berry fruits from two spe... more In this study, the content composition and antioxidant activity of goji berry fruits from two species (Lycium barbarum and Lycium chinense) were assessed. The total carbohydrate and phenolic contents were evaluated using attenuated total reflection Fourier-transform infrared (ATR-FT-IR) spectroscopy, while the antioxidant activity of fruits was examined with two in vitro methods, which are based on the scavenging activity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2’-azino-bis(3-ethyl-benzthiazoline-sulfonic acid) (ABTS•+) free radicals. The fatty-acid profile was determined using gas chromatography coupled with mass spectrometry (GC-MS). The results of this study indicate that the fruits of L. barbarum present higher concentrations in carbohydrates and phenolics than L. chinense Mill. fruits. Furthermore, the antioxidant activity based on the half maximal inhibitory concentration (IC50) measurements of DPPH• and ABTS•+ free-radical scavenging was higher in L. barbarum than ...
The cross-influence effects of treatment temperature and time on the wettability of a siloxane el... more The cross-influence effects of treatment temperature and time on the wettability of a siloxane elastomer is investigated in detail, through static and tilt contact angle measurements. The material is heated at 400, 500, 600, 650, 700, and 800 °C for various periods, ranging from 1 to 300 s. The siloxane surface is subjected to multiple wettability transitions with treatment time: from intrinsic hydrophobicity to superhydrophobicity (and water repellency) and then through intermediate stages (hydrophobicity and hydrophilicity) to superhydrophilicity. For the time scale used herein (1-300 s), this scenario is recorded for treatment at 650, 700, and 800 °C. For treatment at lower temperatures (400, 500, and 600 °C) only the first transition, from intrinsic hydrophobicity to superhydrophobicity, is recorded. Scanning electron microscopy, micro-Fourier transform infrared (micro-FTIR), and micro-Raman spectroscopies are employed to correlate the aforementioned wettability transitions with structural and chemical changes of the siloxane surface, developed during thermal treatment. It is shown that the first transition from intrinsic hydrophobicity to superhydrophobicity is accompanied by a severe surface-structure evolution that increases surface roughness. Once superhydrophobicity is achieved, the surface structure reaches a saturation point and it is not subjected to any other change with further thermal treatment. FTIR spectroscopy shows that the intensity of the O-H/C-H peaks increases/decreases with treatment time, and Raman measurements show that the C-Si-C vibrations gradually disappear with treatment time. The evaporation of a droplet resting on a superhydrophobic, water-repellent siloxane surface, which was produced after appropriate thermal treatment, is monitored. It is shown that droplet evaporation initially follows the constant contact area mode. At later evaporation stages, a transition to the constant contact angle mode is recorded. Finally, it is demonstrated that the superhydrophobic and water-repellent siloxane surfaces exhibit self-cleaning properties, good durability, and furthermore do not practically affect the optical transparency of glass substrates.
Abstract. The spin and orbital ordering have been examined for high-quality SmVO3 polycrystalline... more Abstract. The spin and orbital ordering have been examined for high-quality SmVO3 polycrystalline compound using Raman spectroscopy. Measurements were obtained on individual microcrystallites in the approximate y(zz)y ̄ and y(xx)y ̄ scattering configurations at low temperatures (down to 20K). Based on our experimental data we present evidence of a coexistence of the G and C-type OO phases that occur in SmVO3 for temperatures below 100K. This phase coexistence of orbital orderings puts SmVO3 in a different category from all the other RVO3 compounds that have been studied yet. 1.
a b s t r a c t The doping dependence of the Raman spectra of high quality La 2Àx Sr x Cu À1 , $2... more a b s t r a c t The doping dependence of the Raman spectra of high quality La 2Àx Sr x Cu À1 , $280 cm À1 , and $370 cm À1 are activated in the (xx/yy) polarization Raman spectra due to the local breaking of the inversion symmetry mainly at low temperatures and for doping concentrations for which the compound is superconducting. The apparent A 1 -character of the activated modes in the symmetry reduced phase indicates a reduction from the D 2h to C 2v or D 2 crystal symmetries, which associates the observed modes to specific IR-active phonons with eigenvectors mainly along the c-axis. The temperature and doping dependence of this inversion symmetry breaking and the superconducting transition temperature are very similar, though the symmetry reduction occurs at significantly higher temperatures.
Η ανάλυση και ταυτοποίηση των φυσικών οργανικών χρωστικών (βαφών) που περιέχονται σε μικροδείγματ... more Η ανάλυση και ταυτοποίηση των φυσικών οργανικών χρωστικών (βαφών) που περιέχονται σε μικροδείγματα ιστορικών υφασμάτων της πολιτιστικής κληρονομιάς επιτυγχάνεται συνήθως με υγρή χρωματογραφία υψηλής απόδοσης συνδεδεμένη με ανιχνευτή συστοιχίας διόδων ή/και φασματομετρία μαζών (HPLC-DAD-MS). Πριν την εισαγωγή του στη χρωματογραφική διάταξη, το εκάστοτε δείγμα πρέπει να επεξεργαστεί κατάλληλα ώστε να επιτευχθεί απόσπαση των οργανικών χρωστικών από το μέταλλο πρόστυψης του υφάνσιμου υποστρώματος. Η κλασική μέθοδος που χρησιμοποιείται διεθνώς περιλαμβάνει την επεξεργασία του δείγματος με διάλυμα υδροχλωρικού οξέως (HCl). Σε μία πρόσφατη εργασία μας, δείξαμε ότι η αντικατάσταση του ισχυρού HCl με το ηπιότερο τριφθοροοξικό οξύ (TFA) οδηγεί στην καταγραφή πληρέστερων αποτελεσμάτων, καθώς αποφεύγεται η καταστροφή γλυκοσιδικών δεσμών που υπάρχουν σε κάποιες χρωστικές. Στην παρούσα εργασία η καταλληλότητα/υπεροχή της μεθόδου με TFA υποστηρίζεται με επιπλέον δεδομένα που ελήφθησαν από την ανάλυση μικροδειγμάτων τα οποία εξήχθησαν από ιστορικά υφάσματα της Ι.Μ. Ξηροποτάμου του Αγίου Όρους. Συνολικά στα ιστορικά δείγματα βρέθηκαν οι παρακάτω οργανικές χρωστικές: κογχινίλη, κοκκινόξυλο, ρεζεδά, γενίστα, χρυσόξυλο, ινδικό/ίσατις, φουστίκ, φουξίνη και καρμινούχο ινδικό. Ορισμένα από τα δείγματα έφεραν μεταλλικά ελάσματα, τα οποία μελετήθηκαν με Ηλεκτρονική Μικροσκοπία Σάρωσης συνδεδεμένη με Φασματοσκοπία Ενεργειακής Διασποράς Ακτίνων-Χ (SEM-EDX). Στα μεταλλικά μέρη των δειγμάτων εντοπίστηκε μεταξύ των άλλων άργυρος (Ag) και σε ορισμένες περιπτώσεις και χρυσός (Au). Τέλος, φασματοσκοπία μFTIR εφαρμόστηκε σε δύο δείγματα όπου ταυτοποιήθηκε η ανόργανη χρωστική του Μπλε της Πρωσίας.
In this work we provide results of three analytical methods, e.g. micro-RAMAN, micro-FTIR and SEM... more In this work we provide results of three analytical methods, e.g. micro-RAMAN, micro-FTIR and SEM/EDS, which were applied for the identification of pigments in 19th century icons for preservation and restoration purposes. These icons are stored in the Saint George church at the Asvestochori village near Thessaloniki, N. Greece. The two icons depict the “Palpation of Thomas” and St.Dionisios, respectively, and were constructed between 1812 and 1825 to decorate the altar of the church. These icons are works of folk art and their iconographic characteristics are affected by the contemporaneous historic spirit. Thus, the saints are depicted in simple shapes, primary colors are dark and locally mixed with brighter tones to express a hint of joy. Icons are in good conservation status, they exhibit usage and time ravages to their paint layers and wooden bodies. Representative samples, of the pigments, not exceeding dimensions of approximately 2x3x1 mm, from both icons were obtained. These samples were studied using the non-destructive technique of micro-Raman spectroscopy for the identification of inorganic pigments. Micro-FTIR spectroscopy was implemented as a complementary technique for the identification purposes. Finally, where coatings of the binder material on the pigments were hampering the spectroscopy analyses the scanning electron microscopy (SEM/EDS) technique was selectively used. The analytical techniques micro-RAMAN and micro-FTIR were performed in the frame of the “Programme of Management and Conservation of Ecclesiastical Cultural Heritage Objects” at the University Ecclesiastical Academy of Thessaloniki. The SEM/EDS study was applied at the School of Sciences of Aristotle University of Thessaloniki. The main purpose of this study is to improve our scientific knowledge on the pigments which were used at iconography during early 19th century in the broader area of Thessaloniki, by examining inorganic and organic components and when possible to apply these materials in the conservation science.
Uploads
Papers by Dimitrios Lampakis
Ορισμένα από τα δείγματα έφεραν μεταλλικά ελάσματα, τα οποία μελετήθηκαν με Ηλεκτρονική Μικροσκοπία Σάρωσης συνδεδεμένη με Φασματοσκοπία Ενεργειακής Διασποράς Ακτίνων-Χ (SEM-EDX). Στα μεταλλικά μέρη των δειγμάτων εντοπίστηκε μεταξύ των άλλων άργυρος (Ag) και σε ορισμένες περιπτώσεις και χρυσός (Au). Τέλος, φασματοσκοπία μFTIR εφαρμόστηκε σε δύο δείγματα όπου ταυτοποιήθηκε η ανόργανη χρωστική του Μπλε της Πρωσίας.